Intra- and inter-rat co-existence and congestion control for LTE PC5-based vehicle-to-vehicle (V2V) communication

ABSTRACT

Systems and methods of providing RAT co-existence and congestion control in V2V communications are generally described. A vUE detects specific non-LTE RAT transmissions in a listening period of a PSSCH or PSSCH, determines whether a metric has been met and reselects to a non-overloaded channel to communicate with other vUEs or the eNB. The manner of reselection is dependent on the RAT specific or V2X service priorities of the channels, as well as whether the channels are V2V service dependent.

PRIORITY CLAIM

This application is a continuation of U.S. patent application Ser. No.17/032,324, filed Sep. 25, 2020, entitled “INTRA-AND INTER-RATCO-EXISTENCE AND CONGESTION CONTROL FOR LTE PC5-BASED VEHICLE-TO-VEHICLE(V2V), which is a continuation of U.S. patent application Ser. No.16/322,412, filed Jan. 31, 2019, entitled “INTRA- AND INTER-RATCO-EXISTENCE AND CONGESTION CONTROL FOR LTE PCS-BASED VEHICLE-TO-VEHICLE(V2V) 10 COMMUNICATION”, now U.S. Pat. No. 10,820,348, which is a U.S.National Stage Filing under 35 U.S.C. 371 from International ApplicationNo. PCT/US2017/053652, filed Sep. 27, 2017, which claims the benefit ofpriority to U.S. Provisional Patent Application No. 62/402,507, filedSep. 30, 2016, entitled “INTRA- AND INTER-RAT CO-EXISTENCE ANDCONGESTION CONTROL FOR LTE PCS-BASED VEHICLE-TO-VEHICLE (V2V) 10COMMUNICATION,” which are incorporated herein by reference in stheirentirety.

The claims in the instant application are different than those of theparent application or other related applications. The Applicanttherefore rescinds any disclaimer of claim scope made in the parentapplication or any predecessor application in relation to the instantapplication. The Examiner is therefore advised that any such previousdisclaimer and the cited references that it was made to avoid, may needto be revisited. Further, any disclaimer made in the instant applicationshould not be read into or against the parent application or otherrelated applications.

TECHNICAL FIELD

Embodiments pertain to radio access networks. Some embodiments relate tovarious cellular and wireless local area network (WLAN) networks,including Third Generation Partnership Project Long Term Evolution (3GPPLTE) networks and LTE advanced (LTE-A) networks as well as 4^(th)generation (4G) networks and 5^(th) generation (5G) networks. Someembodiments relate to vehicle-to-vehicle (V2V) communications orvehicle-to-anything (V2X) communications.

BACKGROUND

The use of 3GPP LTE systems (including both LTE and LTE-A systems) hasincreased due to both an increase in the types of devices user equipment(UEs) using network resources as well as the amount of data andbandwidth being used by various applications, such as video streaming,operating on these UEs. For example, the growth of network use byInternet of Things (IoT) UEs, which include machine type communication(MTC) devices such as sensors and may use machine-to-machine (M2M)communications, has severely strained network resources. New 3GPPstandard releases related to the next generation network (5G) are takinginto account the massive influx of low-data, high-delay and low powertransmissions.

One type of increasingly popular communication type isvehicle-to-anything (V2X) communications, and in particularvehicle-to-vehicle (V2V) communications. Despite increased interest inthis type of communications, development and standardization of V2Vcommunications remains pending.

BRIEF DESCRIPTION OF THE FIGURES

In the figures, which are not necessarily drawn to scale, like numeralsmay describe similar components in different views. Like numerals havingdifferent letter suffixes may represent different instances of similarcomponents. The figures illustrate generally, by way of example, but notby way of limitation, various embodiments discussed in the presentdocument.

FIG. 1 illustrates an architecture of a system of a network inaccordance with some embodiments.

FIG. 2 illustrates example components of a device in accordance withsome embodiments.

FIG. 3 illustrates example interfaces of baseband circuitry inaccordance with some embodiments.

FIG. 4 is an illustration of a control plane protocol stack inaccordance with some embodiments.

FIG. 5 is an illustration of a user plane protocol stack in accordancewith some embodiments.

FIG. 6 is a block diagram illustrating components, according to someexample embodiments, able to read instructions from a machine-readableor computer-readable medium (e.g., a non-transitory machine-readablestorage medium) and perform any one or more of the methodologiesdiscussed herein.

FIG. 7 illustrates a LTE-V2V subframe in accordance with someembodiments.

FIG. 8 illustrates LTE-V2V subframes in accordance with embodiments.

FIG. 9 illustrates channel switching in accordance with someembodiments.

FIG. 10 illustrates channel switching in accordance with someembodiments.

FIG. 11 illustrates a method of providing V2V communications inaccordance with some embodiments.

DETAILED DESCRIPTION

The following description and the drawings sufficiently illustratespecific embodiments to enable those skilled in the art to practicethem. Other embodiments may incorporate structural, logical, electrical,process, and other to changes. Portions and features of some embodimentsmay be included in, or substituted for, those of other embodiments.Embodiments set forth in the claims encompass all available equivalentsof those claims.

FIG. 1 illustrates an architecture of a system 100 of a network inaccordance with sonic embodiments. The system 100 is shown to include auser equipment (UE) 101 and a UE 102. The UEs 101 and 102 areillustrated as smartphones (e.g., handheld touchscreen mobile computingdevices connectable to one or more cellular networks), but may alsocomprise any mobile or non-mobile computing device, such as PersonalData Assistants (PDAs), pagers, laptop computers, desktop computers,wireless handsets, or any computing device including a wirelesscommunications interface.

In some embodiments, any of the UEs 101 and 102 can comprise an Internetof Things (IoT) UE, which can comprise a network access layer designedfor low-power IoT applications utilizing short-lived UE connections. AnIoT UE can utilize technologies such as machine-to-machine (M2M) ormachine-type communications (MTC) for exchanging data with an MTC serveror device via a public land mobile network (PLMN), Proximity-BasedService (ProSe) or device-to-device (D2D) communication, sensornetworks, or IoT networks. The M2M or MTC exchange of data may be amachine-initiated exchange of data. An IoT network describesinterconnecting IoT UEs, which may include uniquely identifiableembedded computing devices (within the Internet infrastructure), withshort-lived connections. The IoT UEs may execute background applications(e.g., keep-alive messages, status updates, etc.) to facilitate theconnections of the IoT network.

The UEs 101 and 102 may be configured to connect, e.g., communicativelycouple, with a radio access network (RAN) 110—the RAN 110 may be, forexample, an Evolved Universal Mobile Telecommunications System (UMTS)Terrestrial Radio Access Network (E-UTRAN), a NextGen RAN (NG RAN), orsome other type of RAN. The UEs 101 and 102 utilize connections 103 and104, respectively, each of which comprises a physical communicationsinterface or layer (discussed in further detail below); in this example,the connections 103 and 104 are illustrated as an air interface toenable communicative coupling, and can be consistent with cellularcommunications protocols, such as a Global System for MobileCommunications (GSM) protocol, a code-division multiple access (CDMA)network protocol, a Push-to-Talk (PTT) protocol, a PTT over Cellular(POC) protocol, a Universal Mobile Telecommunications System (UMTS)protocol, a 3GPP Long Term Evolution (LTE) protocol, a 5G protocol, aNew Radio (NR) protocol, and the like.

In this embodiment, the UEs 101 and 102 may further directly exchangecommunication data via a ProSe interface 105. The ProSe interface 105may alternatively be referred to as a sidelink interface comprising oneor more logical channels, including but not limited to a PhysicalSidelink Control Channel (PSCCH), a Physical Sidelink Shared Channel(PSSCH), a Physical Sidelink Discovery Channel (PSDCH), and a PhysicalSidelink Broadcast Channel (PSBCH).

The UE 102 is shown to be configured to access an access point (AP) 106via connection 107. The connection 107 can comprise a local wirelessconnection, such as a connection consistent with any IEEE 802.11protocol, wherein the AP 106 would comprise a wireless fidelity (WiFi®)router. In this example, the AP 106 is shown to be connected to theInternet without connecting to the core network of the wireless system(described in further detail below).

The RAN 110 can include one or more access nodes that enable theconnections 103 and 104. These access nodes (ANs) can be referred to asbase stations (BSs), NodeBs, evolved NodeBs (eNBs), next GenerationNodeBs (gigabit NodeBs—gNBs), RAN nodes, and so forth, and can compriseground stations (e.g., terrestrial access points) or satellite stationsproviding coverage within a geographic area (e.g., a cell). The RAN 110may include one or more RAN nodes for providing macrocells, e.g., macroRAN node 111, and one or more RAN nodes for providing femtocells orpicocells (e.g., cells having smaller coverage areas, smaller usercapacity, or higher bandwidth compared to macrocells), e.g., low power(LP) RAN node 112.

Any of the RAN nodes 111 and 112 can terminate the air to interfaceprotocol and can be the first point of contact for the UEs 101 and 102.In some embodiments, any of the RAN nodes 111 and 112 can fulfillvarious logical functions for the RAN 110 including, but not limited to,radio network controller (RNC) functions such as radio bearermanagement, uplink and downlink dynamic radio resource management anddata packet scheduling, and mobility management.

In accordance with some embodiments, the UEs 101 and 102 can beconfigured to communicate using Orthogonal Frequency-DivisionMultiplexing (OFDM) communication signals with each other or with any ofthe RAN nodes 111 and 112 over a multicarrier communication channel inaccordance various communication techniques, such as, but not limitedto, an Orthogonal Frequency-Division Multiple Access (OFDMA)communication technique (e.g., for downlink communications) or a SingleCarrier Frequency Division Multiple Access (SC-FDMA) communicationtechnique (e.g., for uplink and ProSe or sidelink communications),although the scope of the embodiments is not limited in this respect.The OFDM signals can comprise a plurality of orthogonal subcarriers.

In some embodiments, a downlink resource grid can be used for downlinktransmissions from any of the RAN nodes 111 and 112 to the UEs 101 and102, while uplink transmissions can utilize similar techniques. The gridcan be a time-frequency grid, called a resource grid or time-frequencyresource grid, which is the physical resource in the downlink in eachslot. Such a time-frequency plane representation is a common practicefor OFDM systems, which makes it intuitive for radio resourceallocation. Each column and each row of the resource grid corresponds toone OFDM symbol and one OFDM subcarrier, respectively. The duration ofthe resource grid in the time domain corresponds to one slot in a radioframe. The smallest time-frequency unit in a resource grid is denoted asa resource element. Each resource grid comprises a number of resourceblocks, which describe the mapping of certain physical channels toresource elements. Each resource block comprises a collection ofresource elements; in the frequency domain, this may represent thesmallest quantity of resources that currently can be allocated. Thereare several different physical downlink channels that are conveyed usingsuch resource blocks.

The physical downlink shared channel (PDSCH) may can user data andhigher-layer signaling to the UEs 101 and 102. The physical downlinkcontrol channel (PDCCH) may carry information about the transport formatand resource allocations related to the PDSCH channel, among otherthings. It may also inform the UEs 101 and 102 about the transportformat, resource allocation, and H-ARQ (Hybrid Automatic Repeat Request)information related to the uplink shared channel. Typically, downlinkscheduling (assigning control and shared channel resource blocks to theUE 102 within a cell) may be performed at any of the RAN nodes 111 and112 based on channel quality information fed back from any of the UEs101 and 102. The downlink resource assignment information may be sent onthe PDCCH used for (e.g., assigned to) each of the UEs 101 and 102.

The PDCCH may use control channel elements (CCEs) to convey the controlinformation. Before being mapped to resource elements, the PDCCHcomplex-valued symbols may first be organized into quadruplets, whichmay then be permuted using a sub-block interleaver for rate matching.Each PDCCH may be transmitted using one or more of these CCEs, whereeach CCE may correspond to nine sets of four physical resource elementsknown as resource element groups (REGs). Four Quadrature Phase ShiftKeying (QPSK) symbols may be mapped to each REG. The PDCCH can betransmitted using one or more CCEs, depending on the size of thedownlink control information (DCI) and the channel condition. There canbe four or more different PDCCH formats defined in LTE with differentnumbers of CCEs (e.g., aggregation level, L=1, 2, 4, or 8).

Some embodiments may use concepts for resource allocation for controlchannel information that are an extension of the above-describedconcepts. For example, some embodiments may utilize an enhanced physicaldownlink control channel (EPDCCH) that uses PDSCH resources for controlinformation transmission. The EPDCCH may be transmitted using one ormore to enhanced the control channel elements (ECCEs). Similar to above,each ECCE may correspond to nine sets of four physical resource elementsknown as an enhanced resource element groups (EREGs). An ECCE may haveother numbers of EREGs in some situations.

The RAN 110 is shown to be communicatively coupled to a core network(CN) 120—via an S1 interface 113. In embodiments, the CN 120 may be anevolved packet core (EPC) network, a NextGen Packet Core (NPC) network,or some other type of CN. In this embodiment, the S1 interface 113 issplit into two parts: the S1-U interface 114, which carries traffic databetween the RAN nodes 111 and 112 and the serving gateway (S-GW) 122,and the S1-mobility management entity (MME) interface 115, which is asignaling interface between the RAN nodes 111 and 112 and MMEs 121.

In this embodiment, the CN 120 comprises the MMEs 121, the S-GW 122, thePacket Data Network (PDN) Gateway (P-GW) 123, and a home subscriberserver (HSS) 124. The MMEs 121 may be similar in function to the controlplane of legacy Serving General Packet Radio Service (GPRS) SupportNodes (SGSN). The MMEs 121 may manage mobility aspects in access such asgateway selection and tracking area list management. The HSS 124 maycomprise a database for network users, including subscription-relatedinformation to support the network entities' handling of communicationsessions. The CN 120 may comprise one or several HSSs 124, depending onthe number of mobile subscribers, on the capacity of the equipment, onthe organization of the network, etc. For example, the HSS 124 canprovide support for routing/roaming, authentication, authorization,naming/addressing resolution, location dependencies, etc.

The S-GW 122 may terminate the S1 interface 113 towards the RAN 110, androutes data packets between the RAN 110 and the CN 120. In addition, theS-GW 122 may be a local mobility anchor point for inter-RAN nodehandovers and also may provide an anchor for inter-3GPP mobility. Otherresponsibilities may include lawful intercept, charging, and some policyenforcement.

The P-GW 123 may terminate an SGi interface toward a PDN. The P-GW 123may route data packets between the EPC network 123 and external networkssuch as a network including the application server 130 (alternativelyreferred to as application function (AF)) via an Internet Protocol (IP)interface 125. Generally, the application server 130 may be an elementoffering applications that use IP bearer resources with the core network(e.g., UMTS Packet Services (PS) domain, LTE PS data services, etc.). Inthis embodiment, the P-GW 123 is shown to be communicatively coupled toan application server 130 via an IP communications interface 125. Theapplication server 130 can also be configured to support one or morecommunication services (e.g., Voice-over-Internet Protocol (VoIP)sessions, PTT sessions, group communication sessions, social networkingservices, etc.) for the UEs 101 and 102 via the CN 120.

The P-GW 123 may further be a node for policy enforcement and chargingdata collection. Policy and Charging Enforcement Function (PCRF) 126 isthe policy and charging control element of the CN 120. In a non-roamingscenario, there may be a single PCRF in the Home Public Land MobileNetwork (HPLMN) associated with a UE's Internet Protocol ConnectivityAccess Network (IP-CAN) session. In a roaming scenario with localbreakout of traffic, there may be two PCRFs associated with a UE'sIP-CAN session: a Home PCRF (H-PCRF) within a HPLMN and a Visited PCRF(V-PCRF) within a Visited Public Land Mobile Network (VPLMN). The PCRF126 may be communicatively coupled to the application server 130 via theP-GW 123. The application server 130 may signal the PCRF 126 to indicatea new service flow and select the appropriate Quality of Service (QoS)and charging parameters. The PCRF 126 may provision this rule into aPolicy and Charging Enforcement Function (PCEF) (not shown) with theappropriate traffic flow template (TFT) and QoS class of identifier(QCI), which commences the QoS and charging as specified by theapplication server 130.

FIG. 2 illustrates example components of a device 200 in accordance withsome embodiments. In some embodiments, the device 200 may includeapplication circuitry 202, baseband circuitry 204, Radio Frequency (RF)circuitry 206, front-end module (FEM) circuitry 208, one or moreantennas 210, and power management circuitry (PMC) 212 coupled togetherat least as shown. The components of the illustrated device 200 may beincluded in a UE or a RAN node. In some embodiments, the device 200 mayinclude less elements (e.g., a RAN node may not utilize applicationcircuitry 202, and instead include a processor/controller to process IPdata received from an EPC). In some embodiments, the device 200 mayinclude additional elements such as, for example, memory/storage,display, camera, sensor, or input/output (I/O) interface. In otherembodiments, the components described below may be included in more thanone device (e.g., said circuitries may be separately included in morethan one device for Cloud-RAN (C-RAN) implementations).

The application circuitry 202 may include one or more applicationprocessors. For example, the application circuitry 202 may includecircuitry such as, but not limited to, one or more single-core ormulti-core processors. The processor(s) may include any combination ofgeneral-purpose processors and dedicated processors (e.g., graphicsprocessors, application processors, etc.). The processors may be coupledwith or may include memory/storage and may be configured to executeinstructions stored in the memory/storage to enable various applicationsor operating systems to run on the device 200. In some embodiments,processors of application circuitry 202 may process IP data packetsreceived from an EPC.

The baseband circuitry 204 may include circuitry such as, but notlimited to, one or more single-core or multi-core processors. Thebaseband circuitry 204 may include one or more baseband processors orcontrol logic to process baseband signals received from a receive signalpath of the RF circuitry 206 and to generate baseband signals for atransmit signal path of the RF circuitry 206. Baseband processingcircuity 204 may interface with the application circuitry 202 forgeneration and processing of the baseband signals and for controllingoperations of the RF circuitry 206. For example, in some embodiments,the baseband circuitry 204 may include a third generation (3G) basebandprocessor 204A, a fourth generation (4G) baseband processor 204B, a 5Gbaseband processor 204C, or other baseband processor(s) 204D for otherexisting generations, generations in development or to be developed inthe future (e.g., second generation (2G), sixth generation (6G), etc.).The baseband circuitry 204 (e.g., one or more of baseband processors204A-D) may handle various radio control functions that enablecommunication with one or more radio networks via the RF circuitry 206.In other embodiments, some or all of the functionality of basebandprocessors 204A-D may be included in modules stored in the memory 204Gand executed via a Central Processing Unit (CPU) 204E. The radio controlfunctions may include, but are not limited to, signalmodulation/demodulation, encoding/decoding, radio frequency shifting,etc. In some embodiments, modulation/demodulation circuitry of thebaseband circuitry 204 may include Fast-Fourier Transform (FFT),preceding, or constellation mapping/demapping functionality. In someembodiments, encoding/decoding circuitry of the baseband circuitry 204may include convolution, tail-biting convolution, turbo, Viterbi, or LowDensity Parity Check (LDPC) encoder/decoder functionality. Embodimentsof modulation/demodulation and encoder/decoder functionality are notlimited to these examples and may include other suitable functionalityin other embodiments.

In some embodiments, the baseband circuitry 204 may include one or moreaudio digital signal processor(s) (DSP) 204F. The audio DSP(s) 204F maybe include elements for compression/decompression and echo cancellationand may include other suitable processing elements in other embodiments.Components of the baseband circuitry may be suitably combined in asingle chip, a single chipset, or disposed on a same circuit board insome embodiments. In some embodiments, some or all of the constituentcomponents of the baseband circuitry 204 and the application circuitry202 may be implemented together such as, for example, on a system on achip (SOC).

In some embodiments, the baseband circuitry 204 may provide forcommunication compatible with one or more radio technologies. Forexample, in some embodiments, the baseband circuitry 204 may support tocommunication with an evolved universal terrestrial radio access network(EUTRAN) or other wireless metropolitan area networks (WMAN), a wirelesslocal area network (WLAN), a wireless personal area network (WPAN).Embodiments in which the baseband circuitry 204 is configured to supportradio communications of more than one wireless protocol may be referredto as multi-mode baseband circuitry.

RF circuitry 206 may enable communication with wireless networks usingmodulated electromagnetic radiation through a non-solid medium. Invarious embodiments, the RF circuitry 206 may include switches, filters,amplifiers, etc. to facilitate the communication with the wirelessnetwork. RF circuitry 206 may include a receive signal path which mayinclude circuitry to down-convert RF signals received from the FEMcircuitry 208 and provide baseband signals to the baseband circuitry204. RF circuitry 206 may also include a transmit signal path which mayinclude circuitry to up-convert baseband signals provided by thebaseband circuitry 204 and provide RF output signals to the FEMcircuitry 208 for transmission.

In some embodiments, the receive signal path of the RF circuitry 206 mayinclude mixer circuitry 206A, amplifier circuitry 206B and filtercircuitry 206C. In some embodiments, the transmit signal path of the RFcircuitry 206 may include filter circuitry 206C and mixer circuitry206A. RF circuitry 206 may also include synthesizer circuitry 206D forsynthesizing a frequency for use by the mixer circuitry 206A of thereceive signal path and the transmit signal path. In some embodiments,the mixer circuitry 206A of the receive signal path may be configured todown-convert RF signals received from the FEM circuitry 208 based on thesynthesized frequency provided by synthesizer circuitry 206D. Theamplifier circuitry 206B may be configured to amplify the down-convertedsignals and the filter circuitry 206C may be a low-pass filter (LPF) orband-pass filter (BPF) configured to remove unwanted signals from thedown-converted signals to generate output baseband signals. Outputbaseband signals may be provided to the baseband circuitry 204 forfurther processing. In some embodiments, the output baseband signals maybe zero-frequency baseband signals, although this is not a requirement.In some embodiments, mixer circuitry 206A of the receive signal path maycomprise passive mixers, although the scope of the embodiments is notlimited in this respect.

In some embodiments, the mixer circuitry 206A of the transmit signalpath may be configured to up-convert input baseband signals based on thesynthesized frequency provided by the synthesizer circuitry 206D togenerate RF output signals for the FEM circuitry 208. The basebandsignals may be provided by the baseband circuitry 204 and may befiltered by filter circuitry 206C.

In some embodiments, the mixer circuitry 206A of the receive signal pathand the mixer circuitry 206A of the transmit signal path may include twoor more mixers and may be arranged for quadrature downconversion andupconversion, respectively. In some embodiments, the mixer circuitry206A of the receive signal path and the mixer circuitry 206A of thetransmit signal path may include two or more mixers and may be arrangedfor image rejection (e.g., Hartley image rejection). In someembodiments, the mixer circuitry 206A of the receive signal path and themixer circuitry 206A may be arranged for direct downconversion anddirect upconversion, respectively. In some embodiments, the mixercircuitry 206A of the receive signal path and the mixer circuitry 206Aof the transmit signal path may be configured for super-heterodyneoperation.

In some embodiments, the output baseband signals and the input basebandsignals may be analog baseband signals, although the scope of theembodiments is not limited in this respect. In some alternateembodiments, the output baseband signals and the input baseband signalsmay be digital baseband signals. In these alternate embodiments, the RFcircuitry 206 may include analog-to-digital converter (ADC) anddigital-to-analog converter (DAC) circuitry and the baseband circuitry204 may include a digital baseband interface to communicate with the RFcircuitry 206.

In some dual-mode embodiments, a separate radio IC circuitry may beprovided for processing signals for each spectrum, although the scope ofthe embodiments is not limited in this respect.

In some embodiments, the synthesizer circuitry 206D may be afractional-N synthesizer or a fractional N/N+1 synthesizer, although thescope of the embodiments is not limited in this respect as other typesof frequency synthesizers may be suitable. For example, synthesizercircuitry 206D may be a delta-sigma synthesizer, a frequency multiplier,or a synthesizer comprising a phase-locked loop with a frequencydivider.

The synthesizer circuitry 206D may be configured to synthesize an outputfrequency for use by the mixer circuitry 206A of the RF circuitry 206based on a frequency input and a divider control input. In someembodiments, the synthesizer circuitry 206D may be a fractional N/N+1synthesizer.

In some embodiments, frequency input may be provided by a voltagecontrolled oscillator (VCO), although that is not a requirement. Dividercontrol input may be provided by either the baseband circuitry 204 orthe applications processor 202 depending on the desired outputfrequency. In some embodiments, a divider control input (e.g., N) may bedetermined from a look-up table based on a channel indicated by theapplications processor 202.

Synthesizer circuitry 206D of the RF circuitry 206 may include adivider, a delay-locked loop (DLL), a multiplexer and a phaseaccumulator. In sonic embodiments, the divider may be a dual modulusdivider (DMD) and the phase accumulator may be a digital phaseaccumulator (DPA). In some embodiments, the DMD may be configured todivide the input signal by either N or N+1 (e.g., based on a carry out)to provide a fractional division ratio. In some example embodiments, theDLL may include a set of cascaded, tunable, delay elements, a phasedetector, a charge pump and a D-type flip-flop. In these embodiments,the delay elements may be configured to break a VCO period up into Ndequal packets of phase, where Nd is the number of delay elements in thedelay line. In this way, the DLL provides negative feedback to helpensure that the total delay through the delay line is one VCO cycle.

In some embodiments, synthesizer circuitry 206D may be configured togenerate a carrier frequency as the output frequency, while in otherembodiments, the output frequency may be a multiple of the carrierfrequency (e.g., twice the carrier frequency, four times the carrierfrequency) and used in conjunction with quadrature generator and dividercircuitry to generate multiple signals at the carrier frequency withmultiple different phases with respect to each other. In someembodiments, the output frequency may be a LO frequency (fLO). In someembodiments, the RF circuitry 206 may include an IQ/polar converter.

FEM circuitry 208 may include a receive signal path which may includecircuitry configured to operate on RF signals received from one or moreantennas 210, amplify the received signals and provide the amplifiedversions of the received signals to the RF circuitry 206 for furtherprocessing. FEM circuitry 208 may also include a transmit signal pathwhich may include circuitry configured to amplify signals fortransmission provided by the RF circuitry 206 for transmission by one ormore of the one or more antennas 210. In various embodiments, theamplification through the transmit or receive signal paths may be donesolely in the RF circuitry 206, solely in the FEM 208, or in both the RFcircuitry 206 and the FEM 208.

In some embodiments, the FEM circuitry 208 may include a TX/RX switch toswitch between transmit mode and receive mode operation. The REMcircuitry may include a receive signal path and a transmit signal path.The receive signal path of the FEM circuitry may include an LNA toamplify received RF signals and provide the amplified received RFsignals as an output (e.g., to the RF circuitry 206). The transmitsignal path of the FEM circuitry 208 may include a power amplifier (PA)to amplify input RF signals (e.g., provided by RF circuitry 206), andone or more filters to generate RF signals for subsequent transmission(e.g., by one or more of the one or more antennas 210).

In some embodiments, the PMC 212 may manage power provided to thebaseband circuitry 204. In particular, the PMC 212 may controlpower-source selection, voltage scaling, battery charging, or DC-to-DCconversion. The PMC 212 may often be included when the device 200 iscapable of being powered by a battery, for example, when the device isincluded in a UE. The PMC 212 may increase the power conversionefficiency while providing desirable implementation size and heatdissipation characteristics.

While FIG. 2 shows the PMC 212 coupled only with the baseband circuitry204. However, in other embodiments, the PMC 212 may be additionally oralternatively coupled with, and perform similar power managementoperations for, other components such as, but not limited to,application circuitry 202, RF circuitry 206, or FEM 208.

In some embodiments, the PMC 212 may control, or otherwise be part of,various power saving mechanisms of the device 200. For example, if thedevice 200 is in an RRC_Connected state, where it is still connected tothe RAN node as it expects to receive traffic shortly, then it may entera state known as Discontinuous Reception Mode (DRX) after a period ofinactivity. During this state, the device 200 may power down for briefintervals of time and thus save power.

If there is no data traffic activity for an extended period of time,then the device 200 may transition to an RRC_Idle state. In the RRC_Idlestate, the device 200 may disconnect from the network and avoidperforming operations such as channel quality feedback, handover, etc.The device 200 may enter a very low power state and perform paging inwhich the device 200 may periodically wake up to listen to the networkand then power down again. To receive data, the device 200 maytransition back to the RRC_Connceted state.

An additional power saving mode may allow a device to be unavailable tothe network for periods longer than a paging interval (ranging fromseconds to a few hours). During this time, the device is totallyunreachable to the network and may power down completely. Any data sentduring this time incurs a large delay and it is assumed the delay isacceptable.

Processors of the application circuitry 202 and processors of thebaseband circuitry 204 may be used to execute elements of one or moreinstances of a protocol stack. For example, processors of the basebandcircuitry 204, alone or in combination, may be used execute Layer 3,Layer 2, or Layer 1 functionality, while processors of the applicationcircuitry 204 may utilize data (e.g., packet data) received from theselayers and further execute Layer 4 to functionality (e.g., transmissioncommunication protocol (TCP) and user datagram protocol (UDP) layers).As referred to herein, Layer 3 may comprise a radio resource control(RRC) layer, described in further detail below. As referred to herein,Layer 2 may comprise a medium access control (MAC) layer, a radio linkcontrol (RLC) layer, and a packet data convergence protocol (PDCP)layer, described in further detail below. As referred to herein, Layer 1may comprise a physical (PHY) layer of a UE/RAN node, described infurther detail below.

FIG. 3 illustrates example interfaces of baseband circuitry inaccordance with some embodiments. As discussed above, the basebandcircuitry 204 of FIG. 2 may comprise processors 204A-XT04E and a memory204G utilized by said processors. Each of the processors 204A-XT04E mayinclude a memory interface, 304A-XU04E, respectively, to send/receivedata to/from the memory 204G.

The baseband circuitry 204 may further include one or more interfaces tocommunicatively couple to other circuitries/devices, such as a memoryinterface 312 (e.g., an interface to send/receive data to/from memoryexternal to the baseband circuitry 204), an application circuitryinterface 314 (e.g., an interface to send/receive data to/from theapplication circuitry 202 of FIG. 2 ), an RF circuitry interface 316(e.g., an interface to send/receive data to/from RF circuitry 206 ofFIG. 2 ), a wireless hardware connectivity interface 318 (e.g., aninterface to send/receive data to/from Near Field Communication (NFC)components, Bluetooth® components (e.g., Bluetooth® Low Energy), Wi-Fi®components, and other communication components), and a power managementinterface 320 (e.g., an interface to send/receive power or controlsignals to/from the PMC 212).

FIG. 4 is an illustration of a control plane protocol stack inaccordance with some embodiments. In this embodiment, a control plane400 is shown as a communications protocol stack between the UE 101 (oralternatively, the UE 102), the RAN node 111 (or alternatively, the RANnode 112), and the MME 121.

The PHY layer 401 may transmit or receive information used by the MAClayer 402 over one or more air interfaces. The PHY layer 401 may furtherperform link adaptation or adaptive modulation and coding (AMC), powercontrol, cell search (e.g., for initial synchronization and handoverpurposes), and other measurements used by higher layers, such as the RRClayer 405. The PHY layer 401 may still further perform error detectionon the transport channels, forward error correction (FEC)coding/decoding of the transport channels, modulation/demodulation ofphysical channels, interleaving, rate matching, mapping onto physicalchannels, and Multiple Input Multiple Output (MIMO) antenna processing.

The MAC layer 402 may perform mapping between logical channels andtransport channels, multiplexing of MAC service data units (SDUs) fromone or more logical channels onto transport blocks (TB) to be deliveredto PHY via transport channels, de-multiplexing MAC SDUs to one or morelogical channels from transport blocks (TB) delivered from the PHY viatransport channels, multiplexing MAC SDUs onto TBs, schedulinginformation reporting, error correction through hybrid automatic repeatrequest (HARQ), and logical channel prioritization.

The RLC layer 403 may operate in a plurality of modes of operation,including: Transparent Mode (TM), Unacknowledged Mode (UM), andAcknowledged Mode (AM). The RLC layer 403 may execute transfer of upperlayer protocol data units (PDUs), error correction through automaticrepeat request (ARQ) for AM data transfers, and concatenation,segmentation and reassembly of RLC SDUs for UM and AM data transfers.The RLC layer 403 may also execute re-segmentation of RLC data PDUs forAM data transfers, reorder RLC data PDUs for UM and AM data transfers,detect duplicate data for UM and AM data transfers, discard RLC SDUs forUM and AM data transfers, detect protocol errors for AM data transfers,and perform RLC re-establishment.

The PDCP layer 404 may execute header compression and decompression ofIP data, maintain PDCP Sequence Numbers (SNs), perform in-sequencedelivery of upper layer PDUs at re-establishment of lower layers,eliminate duplicates of lower layer SDUs at re-establishment of lowerlayers for radio bearers mapped on RLC AM, cipher and decipher controlplane data, perform integrity protection and integrity verification ofcontrol plane data, control timer-based discard of data. and performsecurity operations (e.g., ciphering, deciphering, integrity protection,integrity verification, etc.).

The main services and functions of the RRC layer 405 may includebroadcast of system information (e.g., included in Master InformationBlocks (MIBs) or System Information Blocks (SIBs) related to thenon-access stratum (NAS)), broadcast of system information related tothe access stratum (AS), paging, establishment, maintenance and releaseof an RRC connection between the UE and E-UTRAN (e.g., RRC connectionpaging, RRC connection establishment, RRC connection modification, andRRC connection release), establishment, configuration, maintenance andrelease of point to point Radio Bearers, security functions includingkey management, inter radio access technology (RAT) mobility, andmeasurement configuration for UE measurement reporting. Said MIBs andSIBs may comprise one or more information elements (IEs), which may eachcomprise individual data fields or data structures.

The UE 101 and the RAN node 111 may utilize a Uu interface (e.g., anLTE-Uu interface) to exchange control plane data via a protocol stackcomprising the PHY layer 401, the MAC layer 402, the RLC layer 403, thePDCP layer 404, and the RRC layer 405.

The non-access stratum (NAS) protocols 406 form the highest stratum ofthe control plane between the UE 101 and the MME 121. The NAS protocols406 support the mobility of the UE 101 and the session managementprocedures to establish and maintain IP connectivity between the UE 101and the P-GW 123.

The S1 Application Protocol (S1-AP) layer 415 may support the functionsof the S1 interface and comprise Elementary Procedures (EPs). An EP is aunit of interaction between the RAN node 111 and the CN 120. The S1-APlayer services may comprise two groups: UE-associated services and nonUE-associated services. These services perform functions including, butnot limited to: E-UTRAN Radio Access Bearer (E-RAB) management, UEcapability indication, mobility, NAS signaling transport, RANInformation Management (RIM), and configuration transfer.

The Stream Control Transmission Protocol (SCTP) layer (alternativelyreferred to as the SCTP/IP layer) 414 may ensure reliable delivery ofsignaling messages between the RAN node 111 and the MME 121 based, inpart, on the IP protocol, supported by the IP layer 413. The L2 layer412 and the L1 layer 411 may refer to communication links (e.g., wiredor wireless) used by the RAN node and the MME to exchange information.

The RAN node 111 and the MME 121 may utilize an S1-MME interface toexchange control plane data via a protocol stack comprising the L1 layer411, the L2 layer 412, the IP layer 413, the SCTP layer 414, and theS1-AP layer 415.

FIG. 5 is an illustration of a user plane protocol stack in accordancewith some embodiments. In this embodiment, a user plane 500 is shown asa communications protocol stack between the UE 101 (or alternatively,the UE 102), the RAN node 111 (or alternatively, the RAN node 112), theS-GW 122, and the P-GW 123. The user plane 500 may utilize at least someof the same protocol layers as the control plane 400. For example, theUE 101 and the RAN node 111 may utilize a Uu interface (e.g., an LTE-Uuinterface) to exchange user plane data via a protocol stack comprisingthe PHY layer 401, the MAC layer 402, the RLC layer 403, the PDCP layer404.

The General Packet Radio Service (GPRS) Tunneling Protocol for the userplane (GWP-U) layer 504 may be used for carrying user data within theGPRS core network and between the radio access network and the corenetwork. The user data transported can be packets in any of IPv4, IPv6,or PPP formats, for example. The UDP and IP security (UDP/IP) layer 503may provide checksums for data integrity, port numbers for addressingdifferent functions at the source and destination, and encryption andauthentication on the to selected data flows. The RAN node 111 and theS-GW 122 may utilize an S1-U interface to exchange user plane data via aprotocol stack comprising the L1 layer 411, the L2 layer 412, the UDP/IPlayer 503, and the GTP-U layer 504. The S-GW 122 and the P-GW 123 mayutilize an S5/S8a interface to exchange user plane data via a protocolstack comprising the L1 layer 411, the L2 layer 412, the UDP/IP layer503, and the GTP-U layer 504. As discussed above with respect to FIG. 4, NAS protocols support the mobility of the UE 101 and the sessionmanagement procedures to establish and maintain IP connectivity betweenthe UE 101 and the P-GW 123.

FIG. 6 is a block diagram illustrating components, according to someexample embodiments, able to read instructions from a machine-readableor computer-readable medium (e.g., a non-transitory machine-readablestorage medium) and perform any one or more of the methodologiesdiscussed herein. Specifically, FIG. 6 shows a diagrammaticrepresentation of hardware resources 600 including one or moreprocessors (or processor cores) 610, one or more memory/storage devices620, and one or more communication resources 630, each of which may becommunicatively coupled via a bus 640. For embodiments where nodevirtualization (e.g., NFV) is utilized, a hypervisor 602 may be executedto provide an execution environment for one or more networkslices/sub-slices to utilize the hardware resources 600

The processors 610 (e.g., a central processing unit (CPU), a reducedinstruction set computing (RISC) processor, a complex instruction setcomputing (CISC) processor, a graphics processing unit (GPU), a digitalsignal processor (DSP) such as a baseband processor, an applicationspecific integrated circuit (ASIC), a radio-frequency integrated circuit(RFIC), another processor, or any suitable combination thereof) mayinclude, for example, a processor 612 and a processor 614.

The memory/storage devices 620 may include main memory, disk storage, orany suitable combination thereof. The memory/storage devices 620 mayinclude, but are not limited to any type of volatile or non-volatilememory such as dynamic random access memory (DRAM), static random-accessmemory (SRAM), erasable programmable read-only memory (EPROM),electrically erasable programmable read-only memory (EEPROM), Flashmemory, solid-state storage, etc.

The communication resources 630 may include interconnection or networkinterface components or other suitable devices to communicate with oneor more peripheral devices 604 or one or more databases 606 via anetwork 608. For example, the communication resources 630 may includewired communication components (e.g., for coupling via a UniversalSerial Bus (USB)), cellular communication components, NFC components,Bluetooth® components (e.g., Bluetooth® Low Energy), Wi-Fi® components,and other communication components.

Instructions 650 may comprise software, a program, an application, anapplet, an app, or other executable code for causing at least any of theprocessors 610 to perform any one or more of the methodologies discussedherein. The instructions 650 may reside, completely or partially, withinat least one of the processors 610 (e.g., within the processor's cachememory), the memory/storage devices 620, or any suitable combinationthereof. In some embodiments, the instructions 650 may reside on atangible, non-volatile communication device readable medium, which mayinclude a single medium or multiple media. Furthermore, any portion ofthe instructions 650 may be transferred to the hardware resources 600from any combination of the peripheral devices 604 or the databases 606.Accordingly, the memory of processors 610, the memory/storage devices620, the peripheral devices 604, and the databases 606 are examples ofcomputer-readable and machine-readable media.

As described above, with the advent of smart cars and other advancedvehicles, V2V communications have become a rapidly increasing area ofinterest. LTE-based V2V communication technology is being developed toprovide vehicular Intelligent Transport System (ITS) services to V2Vdevices (or V2X devices). The ITS services may include road safetyservices, which may be among the ITS technology candidates fordeployment. Several ITS technologies may be allowed for deployment inthe same set of frequency channels allocated for ITS services. The ITSservices may be supplied to a vUE via Vehicle-to-Vehicle (V2V),Vehicle-to-Infrastructure (V2I), Vehicle-to-Network (V2N) orVehicle-to-Pedestrian (V2P) communications over a PC5 reference point.V2I communications may involve communications with a Road Side Unit(RSU) and V2N communications may involve communications with an eNB. Inorder to provide co-channel coexistence of LTE V2V Radio AccessTechnology (RAT) and other legacy (e.g., Wi-Fi 802.11p-based DedicatedShort Range Communication (DSRC)) or future ITS technologies (e.g., 5Gor New Radio (NR)), it may be desirable to provide the communicationdevice with the ability to detect the presence of a RAT at a specificselected frequency (channel), which, if present, may trigger a frequencychannel reselection process. A frequency channel selection and switchingprocedure may further be provided to minimize the impact of the RATs onone another.

Switching may be used dependent on the load of various channels. Thus,the metrics to measure channel loading may be defined. By defining thechannel loading measurement metrics and establishing a frequency channelselection procedure, the communication devices (hereinafter referred toas vehicle UEs or vUEs) may be able to take congestion measurements anduse the measurements to establish congestion control in the LTE V2Vsystem. In addition, RAT detection and congestion control measurement,in addition to a long-term frequency channel selection and switchingprocedure may enable RAT co-existence and congestion control. Note thatvUEs may be located within vehicles or may be located in otherenvironments (e.g., cell phones).

Various technologies may be used to provide LTE V2V long-term RATco-channel coexistence both with already developed technologies (e.g.IEEE 802.11p/DSRC) and future ITS technologies (e.g. 5G New RAT V2Vtechnologies). These technologies may include the use of a listeninginterval and a specific LTE V2V signal, as well as a mechanism to selector switch the channel to provide co-existence with other RATs. Inparticular, in some embodiments a listening interval used for RATtransmission detection may be introduced. The listening interval mayoccur in the unoccupied last symbol in a V2V subframe. Alternatively, orin addition, the listening interval may occur in a separate, predefinedset of subframes. A new LTE V2V signal may be used during the listeninginterval to detect the LTE V2V transmitters that are in operation at thesame frequency channel. The listening interval may be specific to RATdetection and occur at a different time from detection of referencesignals such as CSI-RS or zero-power (ZP) tracing (or other) referencesignals (ZP-TRS).

RAT co-existence may be obtained using one of a number of differentapproaches. In some embodiments, geo-location and one or more geographicdatabases may be used as different regions may mandate or allow (orplace restrictions on) the use of different technologies. The use ofdifferent databases may permit different technologies to be used indifferent geographical regions. The different geographical regions mayin some embodiments overlap. A vUE may be able to use this approachbased on geo-location information of the vUE, in addition to beingpermitted to dependent on information from database that can bepre-installed in vehicle in which the vUE is located or provided to thevUE by the network. This may be implemented based on the decision of anITS service provider using upper layer communication with the vUE.

Another embodiment for providing RAT co-existence in the system,involves time sharing between systems based on the global navigationsatellite system (GNSS). This may be used for LTE V2V coexistencesolutions with other technologies supporting GNSS. If the vUE has stableGNSS timing, the vUE may be able to continually (e.g., always) apply thetime sharing approach with other technologies in the same frequencychannel. The use of a common timing scheme may permit the different RATsto know the resources used by other RATs. As a fallback technology, ifthe vUE is unable to obtain accurate GNSS timing (either direct orderived), the LTE V2V may switch to frequency channel where LTE-V2V issupposed to operate according to the LTE V2V synchronization procedures.If third-party technology is mandated to use GNSS then this can beapplied to share time resources of a frequency channel withoutcoexistence problems with LTE-V2V.

Another approach is to use sensing-based vacate/switching. Thisco-existence approach assumes that a RAT can detect sharing of the samefrequency channel by other RATs. Two general principles of operation arepossible: technology-agnostic or technology-dependent detection. In thetechnology-agnostic approach, the vUE may avoid detection of the RATtype—instead the vUE may simply determine the presence of another RAT.In the technology-dependent approach, each technology is expected to beable to identify the type of another RAT sharing the channel. This canbe done by analysis of the RAT specific physical layer signals. In somecases, detection of technology type may be impossible for futuretechnologies given that their physical structure is not yet determined.This is to say that the technology-dependent approach may not be forwardcompatible.

However, technology-dependent RAT detection may be flexible enough toenable specific coexistence behavior depending on the type of detectedRAT. The LTE V2V technology of various embodiments may detect any otherexisting ITS technology (e.g., DSRC) with processing of the referencesignals used by the other ITS technology (e.g., a DSRC preamble). Forexample, the DSRC preamble has a predefined structure that can be usedas a DSRC-specific signature and detected using auto- orcross-correlation approaches. To accomplish this, the LTE-V2V receiverbehavior may be modified, for example, in terms of the automatic gaincontrol (AGC) operation which may be updated not only at thetime-aligned subframe boundaries of the LTE system but at the arbitrarytime instance intervals when transmission of DSRC technology istriggered.

As above however, existing technologies may not be able to detect futureRATs due to a causality problem—for example only LTE-V2V technology maybe able to detect DSRC technology, unless additional specification workand functionality is integrated. Assuming that an older technology (e.g.DSRC) may not be able to detect the presence of a LTE-V2V RAT, theLTE-V2V technology may be unable to utilize the capability to recognizethe presence of older technology type and adjust its own radio-layerbehavior to extract mutual benefits for both technologies. Thus, asolution that does not assume technology differentiation may be usedinstead.

Due to these issues, in some cases, a technology-dependent RAT detectionmay be used. For example, the presence of another RAT may be detected bya vUE using an energy monitoring procedure performed in LTE V2V blankresources (i.e., predetermined resources in which no LTE transmissionsare scheduled/intentionally left blank) such as resource elementsreserved for ZP reference signals. The blank resources may be disposedin periodic subframes; in some embodiments, the subframes may be blank.FIG. 7 illustrates a LTE-V2V subframe in accordance with someembodiments. The subframe 700 may be used by any of the devices shown inFIGS. 1-6 . The subframe 700 may be 1 ms in length, although this mayvary in 5G systems. The subframe 700 may contain multiple symbols 702,which in the LTE system may be 14 symbols 702. One of more of thesymbols 702 may contain reference signals, such as demodulationreference signals (DMRS) 704 shown in FIG. 7 .

In one example, the energy measurement may occur at the last symbol 710of the subframe 700. In this case, the LTE-V2V physical structure mayassume puncturing of the last symbol 710 of each subframe 700. Thus,each vUE having a common timing notion may not transmit for the wholesymbol duration at the end of each subframe. This time interval (shownas probe interval 706) could be used by LTE-V2V devices to measurereceived power and to detect the presence of another (e.g., DSRC)technology.

In some embodiments, the energy measurement may occur at specificsubframes, rather than in each subframe. FIG. 8 illustrates LTE-V2Vsubframes in accordance with some embodiments. The subframes 800 may beused by any of the devices shown in FIGS. 1-6 and may have a similarstructure as the subframe shown in FIG. 7 . The subframes 800 mayinclude different sets of LTE-V2V subframes 802, 804, at least some ofwhich may contain non-V2V resources including subframes and/orsub-channels. Energy measurement may occur in the non-V2V resources. TheV2V resource pool configuration may be flexible. Thus, some of thesubframes 804 (or resource elements or symbols in the specificsubframes) may be intentionally left as blank subframes, so that thevUEs do not transmit on those resources. Although the blank subframesmay be configured by the eNB, the blank subframes may occur, forexample, every 100 subframes or several hundred subframes. One or moreblank subframes may occur at each blank subframe location. Themeasurement of received power in these blank resources can be used as anindication of another technology presence. Independent of when theenergy measurement occurs, the timing may be provided to the vUE viahigher layer (e.g., RRC) signaling or an information block, for example.In some embodiments, the vUE may take action (e.g., switching to adifferent frequency) immediately after a measurement of a blank subframeposition finds use by a different RAT, thereby effecting a solution to ashort-teem issue. In some embodiments, the vUE may take action onlyafter a measurement of a predetermined number of blank subframepositions (2 or more) finds use by a different RAT, thereby effecting asolution to a long-term issue.

In some cases, older RAT radio layer behavior may be changed dependingon the presence of a LTE-V2V RAT or in order to simplify coexistencewith future ITS communication technologies. In this case, RAT detectionmay use transmission of an additional LTE-V2V signature signal. Ingeneral, the detection of the LTE-V2V RAT can be done by detecting a LTEV2V sidelink synchronization signal (SLSS) transmission. However, theSLSS transmission periodicity may be relatively long (>160 ms) comparedwith that of other LTE signals, leading to an increased amount of timespend on detection of the SLSS. In addition, detection of LTE V2V SLSSsignals may provide minimal information on the intensity of the LTE V2Vtransmissions.

To this end, the LTE-V2V specific signal (LTE-V2V signature) can beadded at the last symbol of physical sidelink control/shared channel(PSCCH/PSSCH) subframes so that all vUEs transmitting in a givensubframe add the LTE-V2V signature signal at the last (punctured) symbolof the subframe 804. This signal may occupy only a part of the legacysymbol duration (e.g. ½ of legacy symbol duration), as shown in FIG. 7 ,and transmitted by all vUEs at the same set of physical resources.

In some embodiments, the determination of the RAT co-existence may befollowed by frequency channel switching. When the information about theRAT presence is available, the vUEs using the LTE-V2V RAT may performfrequency channel selection or switching. Depending on the frequencychannel allocation, frequency channel selection may be performed indifferent ways.

In some embodiments, a single frequency channel may be allocated toLTE-V2V and DSRC communications. A co-existence solution for fairsharing of resources in this case may use implementation of alisten-before-talk (LBT) like solution. While such a procedure may besimilar to an IEEE 802.11, it may be inconsistent with legacy LTE-V2Vsensing and resource selection procedure.

In some embodiments, multiple frequency channels may be allocated toLTE-V2V and DSRC communications. In this case, multiple channels may beallocated for all technologies with equal priority or differentpriorities may be used. When the channels are allocated with equalpriority, both RAT specific channel loading and overall channel loadingmay be taken into account when switching the channel. FIG. 9 illustrateschannel switching in accordance with some embodiments. The channelswitching scenarios 900 shown may be performed by any of the vUEs inFIGS. 1-6 .

RAT specific channel loading—LRAT (e.g., LLTE-V2V, LDSRC) may betechnology specific in the sense that each technology can measurechannel loading produced by the technology according to atechnology-specific metric (which may differ between the differenttechnologies). For LTE-V2V, there are several approaches to define thismetric, such as reference signal received power (RSRP) measurements overa PSSCH demodulation reference signal (DMRS) (or RSRQ), the amount ofdecoded sidelink control information (SCI) within a predefined timeinterval, and/or the number of resources occupied by vUEs within apredefined time interval, among others. In some cases, for channelactivity indication the amount of decoded SCIs or amount of active vUEs(transmitters) may be suitable. A RSRP threshold may further be appliedwhen the amount of decoded SCIs or active transmitters is evaluated.

Overall channel loading by multiple RATs—LCH may instead or in additionbe used as a metric. This metric may be RAT-independent and characterizethe channel loading occupation by multiple RATs. In some embodiments,the sidelink received signal strength indicator (SL-RSSI) measurementacross the whole system bandwidth can be used to characterize theoverall channel loading. The metric may measure the channel busy ratioevaluated over the predefined time interval on a predetermined set ofresources.

Assuming that multiple channels can be used by both technologies withthe same level of access priority, in some embodiments LTE-V2Vtransmissions may be concentrated in the channel in which LTE-V2Vtransmissions are dominant. This may assume that both channelsexperience a similar loading level. Examples of a similar loading levelmay be limited to general aspects of the channels, i.e., both channelsare not overloaded or both are overloaded, or may be more specific,e.g., the channels are loaded within a predetermined amount or percentof maximum loading. If a significant overall channel loading differenceamong frequency channels is observed, for example one frequency channelis overloaded and another is not overloaded, the non-overloaded channelwith highest RAT loading may be used and the overloaded channel(s)unused.

In situations in which there are more than two channels, the LTE-V2V UEmay preferentially select the non-overloaded channel with higherLLTE-V2V loading (i.e., dominant presence of LTE-V2V transmissions).This is shown in the channel selection scenarios 900 shown in FIG. 9 ,in which in each case (whether two channels or more channels are used),the LTE-V2V UE selects a target non-overloaded channel with higherLTE-V2V loading as long as the channel is not overloaded. In someembodiments, the channel with the highest LTE-V2V loading is selected.In some cases, as shown by the multichannel operation scenarios, thisselection may trigger a secondary selection of the other vUEs (shown asDSRC) from the target channel to a third channel to avoid overloadingthe channel with the total amount of LLTE-V2V and DSRC communications.

As above, in some embodiments, multiple frequency channels may beallocated to LTE-V2V and DSRC communications with RAT-specificpriorities. This is shown in FIG. 10 , which illustrates channelswitching in accordance with some embodiments. The channel switchingscenarios 1000 shown may be performed by any of the vUEs in FIGS. 1-6 .

In this case, each ITS channel may be assigned with atechnology-specific priority. Thus, the vUE channel selection behaviormay be different. In particular, the higher priority may be given to thechannel associated with a higher priority for a given technology(primary channel), even if the overall loading in the lower prioritychannel (secondary channel) is much lower. This is shown, for example,in the lower two channel operation scenarios of FIG. 10 . As above, thisassumes that unless the loading in a higher priority channel is largerthan the predefined level for the LTE RAT, the vUE may continue use thetarget channel; otherwise the vUE can switch to a channel with a lowerpriority. If multiple channels have equal RAT specific priority, theprocedure described in relation to FIG. 9 may be used.

In general, specific V2X services can have different channel assignmentsin terms of channel priority. For example, primary and secondarychannels may be defined per service rather than per RAT. Whileservice-specific priority assignment may complicate the coexistencebehavior, use of a service-specific priority assignment can be a usefultechnique from the intra-RAT channel loading perspective, assuming thata single technology can occupy multiple channels.

Channel selection may he used for intra LTE-V2V congestion control. V2Xservices can be assigned multiple frequency channels for V2Vcommunication. Some embodiments may assume that each V2V service mayhave its own primary channel for V2V communication. In other words,there can be some indication at upper layers on service-specificpriority to utilize the particular channel for a given service delivery.For instance, the primary and secondary channels can be assigned to eachV2V service type. Alternatively, the service-specific channel prioritylevels can be assigned. In any of these scenarios, the vUE can measurethe channel loading by utilizing a congestion metric and select theappropriate frequency channel for communication. If service-specificpriorities are assigned to each channel, the vUE may prioritize thechannel that has higher priority for a given service delivery unless thechannel is overloaded or congested at the radio layer. If the channel isoverloaded, the vUE may select a non-overloaded channel that has thehighest priority for the given V2V service to be delivered.

If multiple channels have equal priority for each V2V service, differentcongestion control techniques may be used. In some embodiments, achannel load balancing technique may be used in which the less congestedchannel is selected. This may not depend on the V2V service distributionacross channels and may reduce congestion at each channel.Alternatively, in some embodiments, a channel may be selected where agiven V2V service has dominant presence. In this case, the selection maybe independent of the channel loading, so long as the channel is notoverloaded.

Congestion control may also be managed by the vUE via the adjustment oftransmit parameters. In a single frequency channel scenario, channelselection congestion control may be unable to be applied. In this casethe radio-layer transmit parameters may be adjusted based on congestioncontrol metric. Various parameters may be controlled to provide coarsegranularity for congestion control, including the maximum number oftransmission time intervals (TTIs) (retransmissions) used per transportblock (TB), the maximum number of sub-channels that can be utilized perTB transmission, the range of effective code rates per TB transmission,and the minimum inter-TB transmission interval.

The various settings or limits may be a function of PC5 congestioncontrol metrics measured by the vUE. This may permit the eNB or upperlayers to provide the settings to be used for sidelink V2Vtransmissions. The parameters may be defined per resource pool and foreach TX priority level.

In some cases, the metrics may provide course congestion control. Forone example, it may take several times to reduce the system load if theinter-TB transmission interval is controlled. In some circumstanceshowever, it may be desirable to control loading with finer granularity.For instance, the system may drop one of N subsequent TBs or drop M of Nsubsequent TBs subject to the minimum distance Dmin between droppedpackets. In this case, each vUE can randomly select one of thetransmission patterns that satisfy the Dmin condition on inter-TBtransmission. This approach can be also implemented in a probabilisticway by configuring the drop probability Pdrop and ensuring that at leastDmin TBs are transmitted before the next upcoming TB can be dropped.

For V2V communication, the vUE may monitor a sensing window of onesecond duration. For resource (re)selection, the vUE may measure thetotal received power measurements on sidelink resources (S-RSSI)(resources allocated by the eNB for sidelink communications) and/or theUE-specific measurement over PSSCH channel transmissions conducted overDMRS signals (PSSCH-RSRP). Either or both measurement types may be usedas a congestion metric. As the LTE PC5 V2V communication assumes timeand frequency division multiplexing within a subframe, the S-RSSImeasurement may be time and frequency selective. The congestion metricmeasurements granularity may be aligned with signal transmissiongranularity, and hence may not be less than one subframe in time and onefrequency sub-channel in frequency. The congestion metric measurementcan be conducted over the PSSCH resources only, or separately over PSCCHand PSSCH resources.

In some embodiments, during the sensing procedure the S-RSSImeasurements may be conducted by the vUE for each subframe that isallocated for PSSCH transmission. Thus, the number of probes can, ingeneral, be equal to the number of time frequency resources within thesensing window. However, geo-location based transmission techniques mayalso factor in, and thus it may be also desirable to perform channelprobing over preconfigured subsets of resources (or pools). This maypermit the eNB to indicate which resources are used to perform S-RSSImeasurements for estimation of channel load. The measurements can bereported to network in order for the network (e.g., eNB) to control thesidelink operation settings.

FIG. 11 illustrates a method of providing V2V communications inaccordance with some embodiments. The method may be performed by thevUEs shown in any of FIGS. 1-6 . In some embodiments, the method may beperformed by the means described above. In some embodiments, the methodto provide V2V communications may contain other operations not shown inFIG. 11 .

At operation 1102, the vUE may communicate over one or more RATs. TheRAT(s) may include, for example, LTE and/or DSRC.

At operation 1104, the vUE may determine whether a listening interval tosense for a V2V signal has occurred. The listening interval may occur,for example, in the unoccupied last symbol in each V2V subframe or in aseparate predefined set of subframes. The V2V signal may be used todetect the LTE V2V transmitters that operate at the same frequency.

At operation 1106, when the vUE determines that the listening intervalhas been reached, the vUE may determine whether a particular metric hasbeen reached. The metrics may be used to measure channel loading on oneor more channels.

At operation 1108, when the vUE determines that the metric has been met,the vUE may select or switch to another frequency channel to provideco-existence with other. The vUE may transmit an indication to the eNBregarding the reselection.

EXAMPLES

Example 1 is an apparatus of a vehicle user equipment (vUE), theapparatus comprising: an interface to send communications to and receivecommunications from at least one of an evolved NodeB (eNB) or anothervUE; and processing circuitry in communication with the interface andarranged to: determine, in a channel of a sidelink subframe used incommunication between vUEs, that a predetermined listening interval hasbeen reached, the channel allocated to a long term evolution (LTE)vehicle-to-vehicle (V2V) radio access technology (RAT), thepredetermined listening interval configured to be devoid of LTE radiofrequency (RF) signals; detect at least one of a V2V or non-V2V signalin the channel during the predetermined listening interval; determinethat a non-LTE RAT is in operation in the channel based on detection ofthe at least one of the V2V or non-V2V signal in the channel during thepredetermined listening interval; and determine whether to one of droppacket transmission or select another channel for transmission. ofmultiple channels allocated to the LTE-V2V RAT and the non-LTE RAT, inresponse to a determination that the non-LTE RAT is in operation in thechannel, the selection based on allocation priorities of the multiplechannels for the LTE-V2V RAT and the non-LTE RAT and conductedmeasurements in a given channel.

In Example 2, the subject matter of Example 1 includes, wherein: thedetection comprises detection of energy of the at least one of the V2Vor non-V2V signal, and the predetermined listening interval is disposedin a last symbol of each of a plurality of contiguous sidelink subframesallocated for cellular V2V communication.

In Example 3, the subject matter of Example 2 includes, wherein: thelast symbol is punctured and the predetermined listening interval isdisposed within a punctured region of the last symbol.

In Example 4, the subject matter of Examples 1-3 includes, wherein: thedetection comprises detection of energy of the V2V signal, and thepredetermined listening interval is disposed in V2V blank reservedresources disposed in preconfigured sidelink subframes.

In Example 5, the subject matter of Examples 1-4 includes, wherein: theV2V signal is a LTE-V2V specific signal transmitted by other vUEs in alast symbol of at least one of a physical sidelink control channel(PSCCH) or physical sidelink shared channel (PSSCH).

In Example 6, the subject matter of Example 5 includes, wherein: thelast symbol is punctured and the signal occupies a part of a last symbolduration.

In Example 7, the subject matter of Examples 1-6 includes, wherein: theLTE-V2V RAT and the non-LTE RAT are allocated with equal priority.

In Example 8, the subject matter of Example 7 includes, wherein: adetermination of whether to drop packet transmission in the givenchannel or select another channel for transmission is dependent on atleast one of RAT-specific channel loading or overall channel loading ofeach of the multiple channels.

In Example 9, the subject matter of Example 8 includes, wherein: thedetermination of whether drop packet transmission in the given channelor select another channel for transmission, as well as which otherchannel to select, is dependent on RAT-specific channel loading, and theRAT-specific channel loading is determined by at least one of referencesignal received power (RSRP) measurements over a physical sidelinkcontrol (PSCCH) or shared channel (PSSCH) demodulation reference signal(DMRS) and comparison with a pre-configured RSRP threshold, an amount ofdecoded sidelink control information (SCI) within a predefined timeinterval, or at least one of a number or ratio of resources detected asoccupied by vUEs within the predefined time interval.

In Example 10, the subject matter of Examples 8-9 includes, wherein: thedetermination of whether drop packet transmission in the given channelor select another channel for transmission, as well as which otherchannel to select, is dependent on overall channel loading, and theoverall channel loading is determined by a sidelink received signalstrength indicator (SL-RSSI) across at least one of an entire systembandwidth or frequency sub-channels configured for sidelink V2Vcommunication, and comparison with pre-configured RSSI threshold.

In Example 11, the subject matter of Examples 8-10 includes, wherein theprocessing circuitry is further arranged to: select to a non-overloadedchannel that has at least one of a highest LTE-V2V RAT priority ordelivered V2V service specific priority among the multiple channels.

In Example 12, the subject matter of Examples 1-11 includes, wherein:the LTE-V2V RAT and the non-LTE RAT are allocated with prioritiesdependent on a type of RAT or vehicle-to-everything (V2X) service type.

In Example 13, the subject matter of Example 12 includes, wherein theprocessing circuitry is further arranged to: select to a non-overloadedchannel that has a highest priority for a particular RAT or V2X servicetype among the multiple channels unless the selection causes thenon-overloaded channel to be overloaded.

In Example 14, the subject matter of Examples 12-13 includes, whereinthe processing circuitry is further arranged to: select to anon-overloaded channel, among the multiple channels, that is dependenton a vehicle-to-anything (V2X) or V2V service provided by the LTE-V2VRAT.

In Example 15, the subject matter of Example 14 includes, wherein: thenon-overloaded channel is a less congested channel when a plurality ofthe channels have equal priority for the V2X or V2V service.

In Example 16, the subject matter of Examples 14-15 includes, whereinthe reselection further comprises: the non-overloaded channel is achannel in which the V2X or V2V service is dominant independent ofchannel congestion unless the selection causes the non-overloadedchannel to be overloaded.

In Example 17, the subject matter of Examples 1-16 includes, wherein theprocessing circuitry is further arranged to: select to a non-overloadedchannel and control at least one congestion control transmissionparameter for sidelink V2V transmissions, the at least one metriccomprising at least one of a maximum number of transmission timeintervals (TTIs) used per transport block (TB), a maximum number ofsub-channels able to be used per TB transmission. a range of effectivecode rates per TB transmission, or a minimum inter-TB transmissioninterval.

In Example 18, the subject matter of Examples 1-17 includes, wherein theprocessing circuitry is further arranged to: select to a non-overloadedchannel dependent on total received power measurements on sidelinkresources.

In Example 19, the subject matter of Example 18 includes, wherein theprocessing circuitry is further arranged to: measure the total receivedpower measurements on sidelink resources comprises one of physicalsidelink shared channel (PSSCH) resources free from a measurement onphysical sidelink control channel (PSCCH) resources or both PSSCH andPSCCH resources.

In Example 20, the subject matter of Example 19 includes, wherein: ameasurement of the total received power measurements on the PSSCHresources occurs over preconfigured subsets of available PSSCHresources.

In Example 21, the subject matter of Examples 1-20 includes, wherein:the processing circuitry comprises a baseband processor configured toencode transmissions to, and decode transmissions from, the eNB or othervUE.

Example 22 is an apparatus of an evolved NodeB (eNB), the apparatuscomprising: an interface to send communications to and receivecommunications from a vehicle user equipment (vUE); and processingcircuitry in communication with the interface and arranged to: encode,for transmission to the vUE, an indication of a predetermined listeninginterval, the listening interval disposed in at least one of a physicalsidelink control channel (PSCCH) or physical sidelink shared channel(PSSCH) and devoid of long term evolution (LTE) radio frequency (RF)signals between the vUE and the eNB; allocate multiple channels to a LTEvehicle-to-vehicle (V2V) radio access technology (RAT), the multiplechannels simultaneously allocated to a non-LTE RAT; and encode, fortransmission to the vUE, an indication at least one metric formeasurement of sidelink V2V transmissions for one of dropping by the vUEof to packet transmission or selection by the vUE from one of themultiple channels to another of the multiple channels in response to themetric being reached.

In Example 23, the subject matter of Example 22 includes, wherein: thepredetermined listening interval is disposed in a last symbol of eachsidelink subframe, during which a LTE-V2V specific signal transmitted byother vUEs occupies a punctured part of a last symbol duration.

In Example 24, the subject matter of Examples 22-23 includes, wherein:the LTE-V2V RAT and the non-LTE RAT are allocated with equal priority,the processing circuitry is further arranged to encode for transmissionto the vUE an indication of whether to select dependent on at least oneof RAT-specific channel loading or overall channel loading of each ofthe multiple channels, selection dependent on RAT-specific channelloading is determined by at least one of reference signal received power(RSRP) measurements over a PSSCH demodulation reference signal (DMRS)and comparison with pre-configured RSRP threshold, an amount of decodedsidelink control information (SCI) within a predefined time interval, ora number of resources occupied by vUEs within the predefined timeinterval, and selection dependent on overall channel loading isdetermined by a sidelink received signal strength indicator (SL-RSSI)across one of an entire system bandwidth or pre-configured sub-channeland comparison with pre-configured RSSI threshold.

In Example 25, the subject matter of Examples 22-24 includes, wherein:the LTE-V2V RAT and the non-LTE RAT are allocated with prioritiesdependent on a type of RAT, and the processing circuitry is furtherarranged to encode for transmission to the vUE an indication to selectto a non-overloaded channel that has a highest priority for a particularRAT among the multiple channels or that is dependent on avehicle-to-anything (V2X) or V2V service provided by the LTE-V2V RAT.

In Example 26, the subject matter of Examples 22-25 includes, wherein:the at least one metric is a congestion control transmission parameterthat comprises at least one of a maximum number of transmission timeintervals (TTIs) used per transport block (TB), a maximum number ofsub-channels that to used per TB transmission, a range of effective coderates per TB transmission, or a minimum inter-TB transmission interval.

In Example 27, the subject matter of Examples 22-26 includes, wherein:the processing circuitry is further arranged to encode for transmissionto the vUE an indication to select to a non-overloaded channel dependenton total received power measurements on PSSCH resources free from ameasurement on PSCCH resources.

Example 28 is a computer-readable storage medium that storesinstructions for execution by one or more processors of a vehicle userequipment (vUE), the one or more processors to configure the vUE to:detect, in a channel allocated to a long term evolution (LTE)vehicle-to-vehicle (V2V) radio access technology (RAT) and to a non-LTERAT, non-LTE RF signals in a punctured region of a last symbol of aphysical sidelink control channel (PSCCH) or physical sidelink sharedchannel (PSSCH) that is configured by the eNB to be devoid of LTE radiofrequency (RF) signals; and select to a non-overloaded channel tocommunicate with at least one of another vUE or the eNB dependent on atleast one metric for sidelink V2V transmissions.

In Example 29, the subject matter of Example 28 includes, wherein: theLTE-V2V RAT and the non-LTE RAT are allocated with equal priority amongmultiple channels, whether to drop transmission or which non-overloadedchannel to select is dependent on at least one of RAT-specific channelloading or overall channel loading of each of the multiple channels,whether to drop transmission or which non-overloaded channel to selectis dependent on RAT-specific channel loading is determined by at leastone of reference signal received power (RSRP) measurements over a PSCCHor PSSCH demodulation reference signal (DMRS), an amount of decodedsidelink control information (SCI) within a predefined time interval, ora number of resources occupied by vUEs within the predefined timeinterval, and selection dependent on overall channel loading isdetermined by a sidelink received signal strength indicator (SL-RSSI)across one of an entire system bandwidth or within pre-configuredsub-channels.

In Example 30, the subject matter of Examples 28-29 includes, wherein atleast one of: the LTE-V2V RAT and the non-LTE RAT are allocated withpriorities dependent on a type of RAT, the at least one metric is acongestion control parameter that comprises at least one of a maximumnumber of transmission time intervals (TTIs) used per transport block(TB), a maximum number of sub-channels that used per TB transmission, arange of effective code rates per TB transmission, or a minimum inter-TBtransmission interval, selection is to a non-overloaded channel that hasa highest priority for a particular RAT among the multiple channels orthat is dependent on a vehicle-to-anything (V2X) or V2V service providedby the LTE-V2V RAT, or selection is to a non-overloaded channel that isdependent on total received power measurements on sidelink resources orPSSCH resources free from a measurement on PSCCH resources.

Example 31 is a method of vehicle-to-vehicle (V2V) communication of avehicle user equipment (vUE), the method comprising: detecting, in achannel allocated to a long term evolution (LTE) V2V radio accesstechnology (RAT) and to a non-LTE RAT, non-LTE RF signals in a puncturedregion of a last symbol of a physical sidelink control channel (PSCCH)or physical sidelink shared channel (PSSCH) that is configured by theeNB to be devoid of LTE radio frequency (RF) signals; and selecting to anon-overloaded channel to communicate with at least one of another vUEor the eNB dependent on at least one metric for sidelink V2Vtransmissions.

In Example 32, the subject matter of Example 31 includes, wherein: theLTE-V2V RAT and the non-LTE RAT are allocated with equal priority amongmultiple channels, whether to drop transmission or which non-overloadedchannel to select is dependent on at least one of RAT-specific channelloading or overall channel loading of each of the multiple channels,whether to drop transmission or which non-overloaded channel to selectis dependent on RAT-specific channel loading is determined by at leastone of reference signal received power (RSRP) measurements over a PSCCHor PSSCH demodulation reference signal (DMRS), an amount of decodedsidelink to control information (SCI) within a predefined time interval,or a number of resources occupied by vUEs within the predefined timeinterval, and selection dependent on overall channel loading isdetermined by a sidelink received signal strength indicator (SL-RSSI)across one of an entire system bandwidth or within pre-configuredsub-channels.

In Example 33, the subject matter of Examples 31-32 includes, wherein atleast one of: the LTE-V2V RAT and the non-LTE RAT are allocated withpriorities dependent on a type of RAT, the at least one metric is acongestion control parameter that comprises at least one of a maximumnumber of transmission time intervals (TTIs) used per transport block(TB), a maximum number of sub-channels that used per TB transmission, arange of effective code rates per TB transmission, or a minimum inter-TBtransmission interval, selection is to a non-overloaded channel that hasa highest priority for a particular RAT among the multiple channels orthat is dependent on a vehicle-to-anything (V2X) or V2V service providedby the LTE-V2V RAT, or selection is to a non-overloaded channel that isdependent on total received power measurements on sidelink resources orPSSCH resources free from a measurement on PSCCH resources.

Example 34 is an apparatus of a vehicle user equipment (vUE), theapparatus comprising: means for detecting, in a channel allocated to along term evolution (LTE) vehicle-to-vehicle (V2V) radio accesstechnology (RAT) and to a non-LTE RAT, non-LTE RF signals in a puncturedregion of a last symbol of a physical sidelink control channel (PSCCH)or physical sidelink shared channel (PSSCH) that is configured by theeNB to be devoid of LTE radio frequency (RF) signals; and means forselecting to a non-overloaded channel to communicate with at least oneof another vUE or the eNB dependent on at least one metric for sidelinkV2V transmissions.

In Example 35, the subject matter of Example 34 includes, wherein: theLTE-V2V RAT and the non-LTE RAT are allocated with equal priority amongmultiple channels, whether to drop transmission or which non-overloadedchannel to select is dependent on at least one of RAT-specific channelloading or overall channel loading of each of the multiple channels,whether to drop transmission or which non-overloaded channel to selectis dependent on RAT-specific channel loading is determined by at leastone of reference signal received power (RSRP) measurements over a PSCCHor PSSCH demodulation reference signal (DMRS), an amount of decodedsidelink control information (SCI) within a predefined time interval, ora number of resources occupied by vUEs within the predefined timeinterval, and selection dependent on overall channel loading isdetermined by a sidelink received signal strength indicator (SL-RSSI)across one of an entire system bandwidth or within pre-configuredsub-channels.

In Example 36, the subject matter of Examples 34-35 includes, wherein atleast one of: the LTE-V2V RAT and the non-LTE RAT are allocated withpriorities dependent on a type of RAT, the at least one metric is acongestion control parameter that comprises at least one of a maximumnumber of transmission time intervals (TTIs) used per transport block(TB), a maximum number of sub-channels that used per TB transmission, arange of effective code rates per TB transmission, or a minimum inter-TBtransmission interval, selection is to a non-overloaded channel that hasa highest priority for a particular RAT among the multiple channels orthat is dependent on a vehicle-to-anything (V2X) or V2V service providedby the LTE-V2V RAT, or selection is to a non-overloaded channel that isdependent on total received power measurements on sidelink resources orPSSCH resources free from a measurement on PSCCH resources.

Example 37 is at least one machine-readable medium includinginstructions that, when executed by processing circuitry, cause theprocessing circuitry to perform operations to implement of any ofExamples 1-36.

Example 38 is an apparatus comprising means to implement of any ofExamples 1-36.

Example 39 is a system to implement of any of Examples 1-36.

Example 40 is a method to implement of any of Examples 1-36.

Although an embodiment has been described with reference to specificexample embodiments, it will be evident that various modifications andchanges may be made to these embodiments without departing from thebroader scope of the present disclosure. Accordingly, the specificationand drawings are to be regarded in an illustrative rather than arestrictive sense. The accompanying drawings that form a part hereofshow, by way of illustration, and not of limitation, specificembodiments in which the subject matter may be practiced. Theembodiments illustrated are described in sufficient detail to enablethose skilled in the art to practice the teachings disclosed herein.Other embodiments may be utilized and derived therefrom, such thatstructural and logical substitutions and changes may be made withoutdeparting from the scope of this disclosure. This Detailed Description,therefore, is not to be taken in a limiting sense, and the scope ofvarious embodiments is defined only by the appended claims, along withthe full range of equivalents to which such claims are entitled.

The subject matter may be referred to herein, individually and/orcollectively, by the term “embodiment” merely for convenience andwithout intending to voluntarily limit the scope of this application toany single inventive concept if more than one is in fact disclosed.Thus, although specific embodiments have been illustrated and describedherein, it should be appreciated that any arrangement calculated toachieve the same purpose may be substituted for the specific embodimentsshown. This disclosure is intended to cover any and all adaptations orvariations of various embodiments. Combinations of the aboveembodiments, and other embodiments not specifically described herein,will be apparent to those of skill in the art upon reviewing the abovedescription.

In this document, the terms “a” or “an” are used, as is common in patentdocuments, to include one or more than one, independent of any otherinstances or usages of “at least one” or “one or more.” In thisdocument, the term “or” is used to refer to a nonexclusive or, such that“A or B” includes “A but not B,” “B but not A,” and “A and B,” unlessotherwise indicated. In this document, the terms “including” and “inwhich” are used as the plain-English equivalents of the respective terms“comprising” and “wherein.” Also, in the following claims, the terms“including” and “comprising” are open-ended, that is, a system, UE,article, composition, formulation, or process that includes elements inaddition to those listed after such a term in a claim are still deemedto fall within the scope of that claim. Moreover, in the followingclaims, the terms “first,” “second,” and “third,” etc. are used merelyas labels, and are not intended to impose numerical requirements ontheir objects.

The Abstract of the Disclosure is provided to comply with 37 C.F.R. §1.72(b), requiring an abstract that will allow the reader to quicklyascertain the nature of the technical disclosure. It is submitted withthe understanding that it will not be used to interpret or limit thescope or meaning of the claims. In addition, in the foregoing DetailedDescription, it can be seen that various features are grouped togetherin a single embodiment for the purpose of streamlining the disclosure.This method of disclosure is not to be interpreted as reflecting anintention that the claimed embodiments require more features than areexpressly recited in each claim. Rather, as the following claimsreflect, inventive subject matter lies in less than all features of asingle disclosed embodiment. Thus, the following claims are herebyincorporated into the Detailed Description, with each claim standing onits own as a separate embodiment.

What is claimed is:
 1. A method for a base station to allocate at leastone sub-channel for device-to-device (D2D) communication, comprising:transmitting, to a user equipment device (UE), an indication of the atleast one sub-channel and resource pools the UE uses for communicationwith other UEs and not for transmissions to the base station, whereinthe resource pools are disposed in a physical sidelink channel; andtransmitting, to the UE, an indication of at least one metric formeasurement of D2D transmissions for adjustment of transmissionparameters on the at least one allocated sub-channel and the resourcepools.
 2. The method of claim 1, further comprising: allocating the atleast one sub-channel to D2D communication.
 3. The method of claim 1,wherein said transmitting, to the UE, the indication of the at least onemetric for measurement of D2D transmissions for adjustment oftransmission parameters is in response to measurement of the at leastone metric by the UE.
 4. The method of claim 1, further comprising:providing transmission parameters to the UE for the D2D communication.5. The method of claim 1, wherein the transmission parameters aredefined per resource pool.
 6. The method of claim 1, wherein thetransmission parameters are defined per transmission priority level. 7.The method of claim 1, wherein the physical sidelink channel comprisesat least one of a physical sidelink control channel (PSCCH) or aphysical sidelink shared channel (PSSCH).
 8. A base station, comprising:an interface configured for wireless communication; and a processor incommunication with the interface and configured to cause the basestation to: transmit, to a user equipment device (UE), an indication ofat least one sub-channel and resource pools the UE uses forcommunication with other UEs and not for transmissions to the basestation, wherein the resource pools are disposed in a physical sidelinkchannel; and transmit, to the UE, an indication of at least one metricfor measurement of D2D transmissions for adjustment of transmissionparameters on the at least one sub-channel and the resource pools. 9.The base station of claim 8, wherein the processor is further configuredto cause the base station to: allocate the at least one sub-channel toD2D communication.
 10. The base station of claim 8, wherein theprocessor is further configured to transmit, to the UE, the indicationof the at least one metric for measurement of D2D transmissions foradjustment of transmission parameters in response to measurement of theat least one metric by the UE.
 11. The base station of claim 8, whereinthe processor is further configured to cause the base station to:provide transmission parameters to the UE for the D2D communication. 12.The base station of claim 8, wherein the transmission parameters aredefined per resource pool.
 13. The base station of claim 8, wherein thetransmission parameters are defined per transmission priority level. 14.The base station of claim 8, wherein the physical sidelink channelcomprises at least one of a physical sidelink control channel (PSCCH) ora physical sidelink shared channel (PSSCH).
 15. An apparatus,comprising: a memory; and a processor in communication with the memoryand configured to: transmit, to a user equipment device (UE), anindication of at least one sub-channel and resource pools the UE usesfor communication with other UEs and not for transmissions to a basestation associated with the apparatus, wherein the resource pools aredisposed in a physical sidelink channel; and transmit, to the UE, anindication of at least one metric for measurement of D2D transmissionsfor adjustment of transmission parameters on the at least onesub-channel and the resource pools.
 16. The apparatus of claim 15,wherein the processor is further configured to: allocate the at leastone sub-channel to D2D communication.
 17. The apparatus of claim 15,wherein the processor is further configured to: provide transmissionparameters to the UE for the D2D communication.
 18. The apparatus ofclaim 15, wherein the transmission parameters are defined per resourcepool.
 19. The apparatus of claim 15, wherein the transmission parametersare defined per transmission priority level.
 20. The apparatus of claim15, wherein the physical sidelink channel comprises at least one of aphysical sidelink control channel (PSCCH) or a physical sidelink sharedchannel (PSSCH).